Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, P.R. China.
Analyst. 2019 Sep 9;144(18):5394-5403. doi: 10.1039/c9an00669a.
Lateral flow assays (LFAs) are promising candidates in biomedical diagnosis fields due to their rapid, low-cost, and portable features. However, improving their sensitivity remains challenging due to the unclear roles of capture probes with different distribution formats on the particle transfer and capturing in the test line. Therefore, we designed experiments and observed an asymmetrical U-shaped distribution of control probes throughout the NC membrane thickness. Based on this outcome, a two-dimensional mathematical model based on the Langmuir surface reaction kinetics was developed to investigate the effect of capture probe distributions on LFA performance. A two-dimensional model was qualitatively validated by comparing with the experimental results and the simulations of the reported one-dimensional model. Then, a higher detection signal was achieved by using the U-shaped distribution of capture probes throughout the NC membrane thickness instead of a uniform distribution. Furthermore, when the NC membrane thickness was less than 110 μm, the ratio of the detection signal in the visible region to the signal in the total section at the test line was above 13%. A thin NC membrane will produce a strong detection signal in the visible region at the test line. The developed model is capable of providing direct predictions in designing highly sensitive LFAs.
侧向流检测（LFA）因其快速、低成本和便携的特点，在生物医学诊断领域具有很大的应用潜力。然而，由于不同分布格式的捕获探针在检测线上的颗粒传递和捕获中的作用不明确，提高其灵敏度仍然具有挑战性。因此，我们设计了实验，并观察到控制探针在整个 NC 膜厚度上呈不对称的 U 形分布。基于这一结果，我们建立了一个基于 Langmuir 表面反应动力学的二维数学模型，以研究捕获探针分布对 LFA 性能的影响。二维模型通过与实验结果和报道的一维模型的模拟进行定性验证。然后，通过在整个 NC 膜厚度上使用 U 形分布的捕获探针而不是均匀分布，实现了更高的检测信号。此外，当 NC 膜厚度小于 110 μm 时，检测线上可见区域的检测信号与总截面信号的比值大于 13%。在检测线上，较薄的 NC 膜将产生较强的可见区域检测信号。所开发的模型能够在设计高灵敏度的 LFA 方面提供直接的预测。
